I have 2 of these cams in operation without any problems. However, setting them up is not that easy.
It is important to first connect the smartphone to the camera's Wi-Fi and then enter the password for your own network.
In the camera settings (More / Network), activate Obtain IP address from DHCP server.
This should actually work.

Our camera gets lost all the time. See if you can assign static addresses. Probably both cams run under the same IP. In the camera's settings and in your own router. Then it should work.